distributed 1.3.0

CQRS/ES framework for Rust using Plain Old Rust Structs — append-only events, replay, snapshots, outbox, service bus, and pluggable infrastructure
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123

use distributed::emitter::EntityEmitter;
use distributed::{digest, enqueue, Entity};

/// An aggregate using both #[digest] and #[enqueue] — the typical pattern.
/// Events are recorded to the entity stream for replay AND queued for
/// in-process choreography emission.
pub struct Order {
    pub entity: Entity,
    pub emitter: EntityEmitter,
    pub order_id: String,
    pub customer: String,
    pub status: String,
}

impl Default for Order {
    fn default() -> Self {
        Self {
            entity: Entity::new(),
            emitter: EntityEmitter::default(),
            order_id: String::new(),
            customer: String::new(),
            status: String::new(),
        }
    }
}

impl Order {
    #[digest("OrderCreated")]
    #[enqueue("OrderCreated")]
    pub fn create(&mut self, order_id: String, customer: String) {
        self.entity.set_id(&order_id);
        self.order_id = order_id;
        self.customer = customer;
        self.status = "created".into();
    }

    #[digest("OrderConfirmed", when = self.status == "created")]
    #[enqueue("OrderConfirmed", when = self.status == "created")]
    pub fn confirm(&mut self) {
        self.status = "confirmed".into();
    }

    #[digest("OrderShipped", when = self.status == "confirmed")]
    #[enqueue("OrderShipped", when = self.status == "confirmed")]
    pub fn ship(&mut self) {
        self.status = "shipped".into();
    }
}

distributed::aggregate!(Order, entity {
    "OrderCreated"(order_id, customer) => create,
    "OrderConfirmed"() => confirm(),
    "OrderShipped"() => ship(),
});

/// An aggregate using #[enqueue] with a custom emitter field name.
pub struct Notifier {
    pub entity: Entity,
    pub my_emitter: EntityEmitter,
    pub message: String,
}

impl Default for Notifier {
    fn default() -> Self {
        Self {
            entity: Entity::new(),
            my_emitter: EntityEmitter::default(),
            message: String::new(),
        }
    }
}

impl Notifier {
    #[digest("NotificationSent")]
    #[enqueue(my_emitter, "NotificationSent")]
    pub fn send(&mut self, id: String, message: String) {
        self.entity.set_id(&id);
        self.message = message;
    }
}

distributed::aggregate!(Notifier, entity {
    "NotificationSent"(id, message) => send,
});

/// An aggregate using only #[enqueue] without #[digest] — valid but uncommon.
/// Useful when you want local event choreography without persisted event history.
pub struct Ephemeral {
    pub entity: Entity,
    pub emitter: EntityEmitter,
    pub value: String,
}

impl Default for Ephemeral {
    fn default() -> Self {
        Self {
            entity: Entity::new(),
            emitter: EntityEmitter::default(),
            value: String::new(),
        }
    }
}

impl Ephemeral {
    #[enqueue("ValueSet")]
    pub fn set_value(&mut self, value: String) {
        self.value = value;
    }

    #[enqueue("ValueCleared", when = !self.value.is_empty())]
    pub fn clear(&mut self) {
        self.value = String::new();
    }

    #[enqueue("ValueChecked")]
    pub fn check_with_tail_expression(&mut self) {
        self.tail_check()?
    }

    fn tail_check(&self) -> distributed::SourcedResult {
        Ok(())
    }
}